Change style changes to camelCase, fixes Button mock component issue
where Shape changes don't work in Firefox. Also gets past an asset in
GWT dev mode.

Change-Id: I324de1d62f4a91c5c2d29ad7fb675aafaf426314
Upgrade:
  - Upgrade to twitter4j version 3.0.3 which is fully compatible with Twitter API 1.1, in which Search is now a REST endpoint.
Fixes:
  - Authentication problems with stored tokens when re-starting the app
  - Authentication problems with Twitter service not finishing the auth process successfully
  - Adding checks to methods to make sure the user is authenticated and avoiding crashing the app if not

Change-Id: Ifdbdf35f792553fe5325e10d5dac3127900299fc
Add type checking to list argument in foreach. Create a test to check
that the error is caught.

Change-Id: Id032cd6fb1e27040b86337c71180eab098beb00b
Added Slider visible component. A Slider is like a ProgressBar that adds
a draggable thumb. You can touch the thumb and drag left or right to set the
current slider position. This triggers PositionChanged, reporting current
position of the slider thumb.
The slider has min, max and initialPosition properties.
The reported thumb position can be used to dynamically change another
component property; such as TextBox font size or Ball radius.

Change-Id: I30d6714c3b6307776c6b211ae8797cd0c81edec8
Fix for Image mock component issue where doing a Pixel size didn't show a resize for the image in Designer.

Change-Id: Ie1d66f1997b60b2e9f82ba500c3c2e42d36386a5